pfluger



(No Model.)

0. A. PPLUGER.

ELECTRIC ARC LAMP AND CARBON.

No. 540,333. Patented June/l, 1895.

77157015525 Tnve 71(07.

UNITED STATES PATENT OFFICE.

CHARLES A. PFLUGER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE STANDARDELECTRIC COMPANY, OF SAME PLACE.

ELECTRIC-ARC LAMP AND CARBON.

SPECIFICATION forming part of Letters Patent No. 540,883, dated June 4,1895.

Application filed October 13,1894.

To aZZ whom it may concern:

Be it known that I, CHARLES A. PFLUGER, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Eleotric-Arc Lamps andCarbons, of which the followingis a specification.

My invention relates to electric arc lamps and carbons and has for itsobject to provide certain new and useful improvements in lamps andcarbons whereby long and steady burning lamps are produced. I employ alamp substantially as indicated, having two electrodes, each preferablyoblong or elliptical in cross-section, although the form may be slightlychanged. The carbon is preferably, however, of such shape that itsopposite diameters are in the proportion of one to two, the shorterbeing about equal to the diameter of an ordinary single carbon. Thesecarbons I make compound or of a varying texture, the carbon toward thecenter being composed of a finer or softer material. In the use of suchcarbons the arc is adapted to travel back and forth between the two, andexperience has shown that where these carbons are made of a uniformtexture throughout there will be a certain amount of irregularity in theburning incident to the fact, perhaps, that the are 0 at differentpoints along its travel is located between varying volumes of carbon allthe carbon being of the same texture or character. These difficultiesappear to be largely obviated in the case of a lamp such as is here 5shown, by the use of the filling or core of carbon of a differenttexture. In the case of such carbons, one at each electrode, and whenused with an ordinary lamp, I find that the arc travels steadily backand forth across 49 such inner carbon material and with a steady regularmotion and light.

Serial No, 525,807. (No model.)

My invention is illustrated in the accent panying drawings, whereinFigure l is a side elevation of a lamp, showing the electrodescontaining my improve- 4 ment. Fig. 2 is a cross-section through anelliptical electrode, and Fig. 3 is a cross-section through an electrodehaving a series of cores therethrough.

As before suggested the electrode need not 50 be ellipticalin crosssection, nor is it absolutely necessary that the entire core becontinuous, as it may be divided into sections. The wall of interveningmaterial, however, should be thin, at least thin enough to bring 5;; theseveral portions of the core so close together that the uniformity abovereferred to as desired to be obtained is secured.

A is the lamp frame; B C, the carbons; D, the carbon controllingmechanism; E and F, the inner carbon material arranged as shown.

I claim- 1. In an arc lamp the combination of the feeding mechanism withtwo carbon elec trodes each of which is oblong in cross section andformed of carbon having a varying texture from the external surfacetoward the center.

2. In an arc lamp the combination of a carbon feeding mechanism with twoelectrodes 7o each elliptical in orosssection and composed of an outerwall of carbon with an inner car- ,bon material also elliptical incross-section and varying in texture from the outer wall.

Signed at Chicago, October 10, 189$.

CHARLES A. PFLUGER.

In presence of JNo. H. OoULTnR, FRANCIS M. IRELAND.

